diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/phy/freescale/phy-fsl-imx8m-pcie.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/drivers/phy/freescale/phy-fsl-imx8m-pcie.c b/drivers/phy/freescale/phy-fsl-imx8m-pcie.c new file mode 100644 index 000000000..c93286483 --- /dev/null +++ b/drivers/phy/freescale/phy-fsl-imx8m-pcie.c @@ -0,0 +1,244 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2021 NXP + */ + +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/mfd/syscon.h> +#include <linux/mfd/syscon/imx7-iomuxc-gpr.h> +#include <linux/module.h> +#include <linux/phy/phy.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/reset.h> + +#include <dt-bindings/phy/phy-imx8-pcie.h> + +#define IMX8MM_PCIE_PHY_CMN_REG061 0x184 +#define ANA_PLL_CLK_OUT_TO_EXT_IO_EN BIT(0) +#define IMX8MM_PCIE_PHY_CMN_REG062 0x188 +#define ANA_PLL_CLK_OUT_TO_EXT_IO_SEL BIT(3) +#define IMX8MM_PCIE_PHY_CMN_REG063 0x18C +#define AUX_PLL_REFCLK_SEL_SYS_PLL GENMASK(7, 6) +#define IMX8MM_PCIE_PHY_CMN_REG064 0x190 +#define ANA_AUX_RX_TX_SEL_TX BIT(7) +#define ANA_AUX_RX_TERM_GND_EN BIT(3) +#define ANA_AUX_TX_TERM BIT(2) +#define IMX8MM_PCIE_PHY_CMN_REG065 0x194 +#define ANA_AUX_RX_TERM (BIT(7) | BIT(4)) +#define ANA_AUX_TX_LVL GENMASK(3, 0) +#define IMX8MM_PCIE_PHY_CMN_REG75 0x1D4 +#define PCIE_PHY_CMN_REG75_PLL_DONE 0x3 +#define PCIE_PHY_TRSV_REG5 0x414 +#define PCIE_PHY_TRSV_REG5_GEN1_DEEMP 0x2D +#define PCIE_PHY_TRSV_REG6 0x418 +#define PCIE_PHY_TRSV_REG6_GEN2_DEEMP 0xF + +#define IMX8MM_GPR_PCIE_REF_CLK_SEL GENMASK(25, 24) +#define IMX8MM_GPR_PCIE_REF_CLK_PLL FIELD_PREP(IMX8MM_GPR_PCIE_REF_CLK_SEL, 0x3) +#define IMX8MM_GPR_PCIE_REF_CLK_EXT FIELD_PREP(IMX8MM_GPR_PCIE_REF_CLK_SEL, 0x2) +#define IMX8MM_GPR_PCIE_AUX_EN BIT(19) +#define IMX8MM_GPR_PCIE_CMN_RST BIT(18) +#define IMX8MM_GPR_PCIE_POWER_OFF BIT(17) +#define IMX8MM_GPR_PCIE_SSC_EN BIT(16) +#define IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE BIT(9) + +struct imx8_pcie_phy { + void __iomem *base; + struct clk *clk; + struct phy *phy; + struct regmap *iomuxc_gpr; + struct reset_control *reset; + u32 refclk_pad_mode; + u32 tx_deemph_gen1; + u32 tx_deemph_gen2; + bool clkreq_unused; +}; + +static int imx8_pcie_phy_power_on(struct phy *phy) +{ + int ret; + u32 val, pad_mode; + struct imx8_pcie_phy *imx8_phy = phy_get_drvdata(phy); + + reset_control_assert(imx8_phy->reset); + + pad_mode = imx8_phy->refclk_pad_mode; + /* Set AUX_EN_OVERRIDE 1'b0, when the CLKREQ# isn't hooked */ + regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14, + IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE, + imx8_phy->clkreq_unused ? + 0 : IMX8MM_GPR_PCIE_AUX_EN_OVERRIDE); + regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14, + IMX8MM_GPR_PCIE_AUX_EN, + IMX8MM_GPR_PCIE_AUX_EN); + regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14, + IMX8MM_GPR_PCIE_POWER_OFF, 0); + regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14, + IMX8MM_GPR_PCIE_SSC_EN, 0); + + regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14, + IMX8MM_GPR_PCIE_REF_CLK_SEL, + pad_mode == IMX8_PCIE_REFCLK_PAD_INPUT ? + IMX8MM_GPR_PCIE_REF_CLK_EXT : + IMX8MM_GPR_PCIE_REF_CLK_PLL); + usleep_range(100, 200); + + /* Do the PHY common block reset */ + regmap_update_bits(imx8_phy->iomuxc_gpr, IOMUXC_GPR14, + IMX8MM_GPR_PCIE_CMN_RST, + IMX8MM_GPR_PCIE_CMN_RST); + usleep_range(200, 500); + + if (pad_mode == IMX8_PCIE_REFCLK_PAD_INPUT || + pad_mode == IMX8_PCIE_REFCLK_PAD_UNUSED) { + /* Configure the pad as input */ + val = readl(imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG061); + writel(val & ~ANA_PLL_CLK_OUT_TO_EXT_IO_EN, + imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG061); + } else { + /* Configure the PHY to output the refclock via pad */ + writel(ANA_PLL_CLK_OUT_TO_EXT_IO_EN, + imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG061); + } + + if (pad_mode == IMX8_PCIE_REFCLK_PAD_OUTPUT || + pad_mode == IMX8_PCIE_REFCLK_PAD_UNUSED) { + /* Source clock from SoC internal PLL */ + writel(ANA_PLL_CLK_OUT_TO_EXT_IO_SEL, + imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG062); + writel(AUX_PLL_REFCLK_SEL_SYS_PLL, + imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG063); + val = ANA_AUX_RX_TX_SEL_TX | ANA_AUX_TX_TERM; + writel(val | ANA_AUX_RX_TERM_GND_EN, + imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG064); + writel(ANA_AUX_RX_TERM | ANA_AUX_TX_LVL, + imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG065); + } + + /* Tune PHY de-emphasis setting to pass PCIe compliance. */ + if (imx8_phy->tx_deemph_gen1) + writel(imx8_phy->tx_deemph_gen1, + imx8_phy->base + PCIE_PHY_TRSV_REG5); + if (imx8_phy->tx_deemph_gen2) + writel(imx8_phy->tx_deemph_gen2, + imx8_phy->base + PCIE_PHY_TRSV_REG6); + + reset_control_deassert(imx8_phy->reset); + + /* Polling to check the phy is ready or not. */ + ret = readl_poll_timeout(imx8_phy->base + IMX8MM_PCIE_PHY_CMN_REG75, + val, val == PCIE_PHY_CMN_REG75_PLL_DONE, + 10, 20000); + return ret; +} + +static int imx8_pcie_phy_init(struct phy *phy) +{ + struct imx8_pcie_phy *imx8_phy = phy_get_drvdata(phy); + + return clk_prepare_enable(imx8_phy->clk); +} + +static int imx8_pcie_phy_exit(struct phy *phy) +{ + struct imx8_pcie_phy *imx8_phy = phy_get_drvdata(phy); + + clk_disable_unprepare(imx8_phy->clk); + + return 0; +} + +static const struct phy_ops imx8_pcie_phy_ops = { + .init = imx8_pcie_phy_init, + .exit = imx8_pcie_phy_exit, + .power_on = imx8_pcie_phy_power_on, + .owner = THIS_MODULE, +}; + +static int imx8_pcie_phy_probe(struct platform_device *pdev) +{ + struct phy_provider *phy_provider; + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct imx8_pcie_phy *imx8_phy; + struct resource *res; + + imx8_phy = devm_kzalloc(dev, sizeof(*imx8_phy), GFP_KERNEL); + if (!imx8_phy) + return -ENOMEM; + + /* get PHY refclk pad mode */ + of_property_read_u32(np, "fsl,refclk-pad-mode", + &imx8_phy->refclk_pad_mode); + + if (of_property_read_u32(np, "fsl,tx-deemph-gen1", + &imx8_phy->tx_deemph_gen1)) + imx8_phy->tx_deemph_gen1 = 0; + + if (of_property_read_u32(np, "fsl,tx-deemph-gen2", + &imx8_phy->tx_deemph_gen2)) + imx8_phy->tx_deemph_gen2 = 0; + + if (of_property_read_bool(np, "fsl,clkreq-unsupported")) + imx8_phy->clkreq_unused = true; + else + imx8_phy->clkreq_unused = false; + + imx8_phy->clk = devm_clk_get(dev, "ref"); + if (IS_ERR(imx8_phy->clk)) { + dev_err(dev, "failed to get imx pcie phy clock\n"); + return PTR_ERR(imx8_phy->clk); + } + + /* Grab GPR config register range */ + imx8_phy->iomuxc_gpr = + syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr"); + if (IS_ERR(imx8_phy->iomuxc_gpr)) { + dev_err(dev, "unable to find iomuxc registers\n"); + return PTR_ERR(imx8_phy->iomuxc_gpr); + } + + imx8_phy->reset = devm_reset_control_get_exclusive(dev, "pciephy"); + if (IS_ERR(imx8_phy->reset)) { + dev_err(dev, "Failed to get PCIEPHY reset control\n"); + return PTR_ERR(imx8_phy->reset); + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + imx8_phy->base = devm_ioremap_resource(dev, res); + if (IS_ERR(imx8_phy->base)) + return PTR_ERR(imx8_phy->base); + + imx8_phy->phy = devm_phy_create(dev, NULL, &imx8_pcie_phy_ops); + if (IS_ERR(imx8_phy->phy)) + return PTR_ERR(imx8_phy->phy); + + phy_set_drvdata(imx8_phy->phy, imx8_phy); + + phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); + + return PTR_ERR_OR_ZERO(phy_provider); +} + +static const struct of_device_id imx8_pcie_phy_of_match[] = { + {.compatible = "fsl,imx8mm-pcie-phy",}, + { }, +}; +MODULE_DEVICE_TABLE(of, imx8_pcie_phy_of_match); + +static struct platform_driver imx8_pcie_phy_driver = { + .probe = imx8_pcie_phy_probe, + .driver = { + .name = "imx8-pcie-phy", + .of_match_table = imx8_pcie_phy_of_match, + } +}; +module_platform_driver(imx8_pcie_phy_driver); + +MODULE_DESCRIPTION("FSL IMX8 PCIE PHY driver"); +MODULE_LICENSE("GPL v2"); |